Bulletin of Entomological Research (2007) 97, 533-544

L. Sigsgaard (2007)
Early season natural control of the brown planthopper, Nilaparvata lugens: the contribution and interaction of two spider species and a predatory bug
Bulletin of Entomological Research 97 (5), 533-544
Abstract: Nilaparvata lugens Stål, the Brown Planthopper (BPH), is a major pest in rice. The lycosid Pardosa pseudoannulata (Bösenberg and Strand) and the linyphiid Atypena formosana (Oi) are the early dominant predators in irrigated rice. Later, predatory bugs, including the mirid Cyrtorhinus lividipennis Reuter, become dominant. In unsprayed rice, BPH numbers normally remain low. While P. pseudoannulata is known to be a key natural enemy of BPH, the contribution to BPH reduction by the smaller A. formosana is less well known. Due to the size difference, A. formosana may also be an intraguild prey of P. pseudoannulata. To investigate predation on BPH by the two spider species alone, together and in combination with C. lividipennis, two cage experiments were conducted, the first with adult spiders, the second with immature/unmated spiders. In the latter, spiders were introduced with a delay to allow a better establishment of C. lividipennis. In both experiments, BPH numbers were lowest in treatments with more than one predator species present. Intermediate BPH reduction was obtained with P. pseudoannulata followed by A. formosana and C. lividipennis. While P. pseudoannulata can prey upon large nymphs and adult BPH, A. formosana favour early instar BPH, leading to a more even control across instars in treatments with both spider species. Pardosa pseudoannulata numbers increased more with A. formosana or A. formosana and C. lividipennis present. In contrast, P. pseudoannulata reduced A. formosana and C. lividipennis numbers. The presence of C. lividipennis apparently lessened intraguild predation on A. formosana and may be an intraguild prey of A. formosana. Competition for prey may have added to the antagonistic interactions found. From a biological control perspective, the presence of both spiders in early rice is an advantage for the biological control of BPH in rice. In early rice, results show that A. formosana is an important predator of BPH and, like C. lividipennis, can complement control by P. pseudoannulata and serve as intraguild prey for the latter species.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Lene Sigsgaard

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
population dynamics/ epidemiology
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
general biology - morphology - evolution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Nilaparvata lugens	Rice (Oryza)
Cyrtorhinus lividipennis (predator)	Nilaparvata lugens	Rice (Oryza)
Pardosa pseudoannulata (predator)	Nilaparvata lugens	Rice (Oryza)
Atypena formosana (predator)	Nilaparvata lugens	Rice (Oryza)